1. Field of the Present Disclosure
The present disclosure relates to an image processing apparatus.
2. Description of the Related Art
In order to remove an irregular crease in a document image of a document, an image processing apparatus (a) generates a luminance histogram of the document image, (b) detects the luminance value at the mode in the luminance histogram as a luminance value of a background pixel, (c) detects a predetermined range of the luminance values including the luminance value of a background pixel as a luminance distribution range of a shadow, and (d) replaces luminance values in the luminance distribution range of a shadow to the luminance value of a background pixel.
However, in the aforementioned technique, when a difference between a luminance value of a background and a luminance value of a crease (wrinkle) in a document image is large, the crease is not removed, and among objects other than the crease, an object having a luminance near the luminance value of a background is improperly removed.